Air lift



Jan.v 28,1941. E; L, BOYNTN 2,229,914

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Jan. 28, 1941.4 E. L. BOYNTON 2,229,9M

AIR LIFT yFiled June 23, 19558 5 Sheets-Sheet 2 mur ,a

Jan. z89 w41.

AIR LIFT Filed' June 25. 1938 E. L. BOYNTON 5 sheets-sheet 3 @www Patented Jan. 28, 1941 UNITED STATES PATENT orner.

4 Claims.

My invention pertains to a form of air lift used in connection with deep Well pumping such as in pumping oil wells. My invention is particularly applicable to oil wells of the type in which there is an insufficient gas or other pressure to force the oil to a suiiicient height in the well casing and to supply sufiicient amount of oil to allow pumping by ordinary methods on a rernunerative basis.

It is well known that in order for the oil from oil sands or the like to flow into the perforated casing of the well it is necessary that the hydraulic head or pressure be less in the lower portion of the casing than in the well formation, therefore one of the features of my invention consists of cutting orf or separating the lower portion of the casing from the upper part of the well, then by means of the reduced or partial vacuum of air by a suction or similar equipment at the tcp orf the well., the pressure in the cut-off or separated section of the casing is reduced thus developing an iniiow of oil. This is readily accomplished by inserting a packer or the like a sunicient distance above the bottom of the Well so that the oil may rise through an oil pipe above the packer and in the separated space between the lower and an upper packer.

A further feature of my invention after a suiiicient amount of oil has been accumulated either by the negative pressure in the separated space between the packer or by the pressure in the ormation, a positive air pressure is created by pumping compressed air downwardly into the separated space or chamber. This pressure then drives the oil into an oil pipe leading to the top of the well and forcing such oil upwardly above a check valve. The positive pressure is then cut 01T and the negative pressure or partial vacuum communicated from the top of the Well to the separated chamber again creates an iniiow from the well formation.

Another feature of my invention resides in either providing an indication for control of the alternate flow of compressed air and the rariiication or creation of a partial vacuum through the medium of a float controlling a valve and also controlling an electric signalling or control operated mechanism. In my construction a valve having a float for control of same is located in a ioat valve housing which has a com munication by a pipe extending upwardly adjacent an oil pipe to a position below the upper packer. Thus when the oil reaches a predetermined level in the separated chamber between the two packers, such oil flows downwardly or separated chamber.

`5 Gn the positive air pressure part of the cycle as the oil is forced downwardly it drains from the float valve chamber and as the float drops it closes the outlet valve for the oil from the float valve housing. At the same time the motion of the iioat valve contro-ls electric switches which may give a signal to an operator at the top of the well. Gn such signal apprising the opera-tor to control the positive flow of air under pressure, the exhaust of such air and the creation of the partial vacuum, the electric circuits closing and opening by the switches may be used as release to afford an automatic control of the supply of air under pressure and the creation of the suction or partial vacuum.

A further feature of my invention is providin an automatic control by electric switches operated by the float valve which, by a relay connecticn at the top of the well, govern the application of the compressed air for* the hoisting stroke on the oil and the creation of the rarification or partial vacuum for the inflow of the well oil.

My invention is illustrated in connection with the accompanying drawings, in which:

Fig. 1 is a vertical section showing the portion of a well casing in section with my invention incorporated therein, this showing the part ad jacent an upper packer. These features are shown in elevation and partly broken away.

Fig. 2 is a continuation of the vertical section of Fig. 1 illustrating the portion adjacent and below the lower packer shown in elevation partly broken away illustrating the inlet and bottom standing valve and the float controlled valve.

Fig. 3 is a developed vertical section on the line 3-3 of Fig. 4 of the iioat controlled Valve and its housing.

Fig. 4 is an enlarged section on the line ll-d of Fig. 2 in the direction of the arrows showing in section the oil pipe and in plan the float valve chamber.

Fig. 5 is an electrical and mechanical diagram to illustrate the indicators and air control mechanism at the top of the well actuated through the medium of the operation of the iioat Valve and the electric switches.

In my invention a well casing is designated by the numeral ll. This may be of the usual form and extends downwardly in a well below the broken lower section I2. The well casing may include only a portion of the well or the whole of the well where such casing is employed but in the latter case the casing usually increases in diameter towards the top of the Well. While the section of the casing illustrated is of the same diameter, it will be understood that the upper portion may be of larger diameter than the lower portion. With my invention I employ a standard or conventional string of oil tubing I5. This extends to the top of the well and is connected stand by stand in the ordinary manner for lowering the equipment into the well. Immediately below the lower stand I provide a check valve assembly I6 which may be of a ball type and can be considered as an upper valve. A sub II below the check valve leads to a coupling I8 to which is connected a standard type of packer 20.

Extending below this packer I employ a pipe section 25. This is an oil pipe land continues downwardly as far as desired and adjacent its lower end 26 has the oat valve housing assembly 30 arcuatein cross section mounted on the end 25, this being described in detail hereunder. A joint or coupling 3I is on the lower end of the pipe and in lowering the equipment has la screw threaded connection to a lower pipe 32 on which is mounted a lower packer 33. 'Ihis packer again is of a standard type and not described in detail. A standing valve assembly 35 is connected at the lower end of the pipe 32. This standing valve is illustrated as having a ported seat 36 with a ball 3l tted thereon. A perforated inlet pipe 38 extends below the check valve andI into a section of the well supplied by oil. either by the pressure of the formation or by the pressure in the formation together with the lowered or decreased pressure caused by a vacuum suction as hereunder mentioned.

In the operation of setting the equipment, the lower packer 33 is first set, this being connected to a string of cil tubing. The packer is of a standard character. It is lowered to the desired position, then by a left hand unthreading, the tubing string is removed from the packer, run out of the hole and then a special tool for setting the packer is run in the hole. With the type oi packer I prefer using, this is rmly set by a onequarter turn for this tool. The special tool is then removed. The upper packer is of a type which can be set by the weight oi` the tubing thereon with a quarter turn. In this case I also employ a standard type of packer. The necessary characteristics are that Vthere must be a space ill between the lower end 3 I, that is, the coupling depending from the upper packer, and the pipe end A32 which extends upwardly above the lower packer. This is to allow the free upward ow of oil to ll the space or chamber above the lower packer and extending upwardly around the oil pipe v25 to the desired height towards the upper packer.

In conjunction with my invention I employ `a vertical string or line of air pipe 45 extending downwardly in the well between the oil tubing I5 and the casing i I. This leads to a position below the check valve assembly I6. In order to carry this air pipe below the upper packer, I provide a transverse air connection unit 46 extending inwardly through the pipe section I I from the main pipe 45 and from this there is a downwardly extending internal air pipe 4I which leads through the packer 2B to a position well below the packer and has an air port end 41' leading through the wall of the pipe 25. By this means there is a direct air connection from this port from below the upper packer, that is, from the separated space in the casing between the upper and lower packers to the top of the well. The upper` or downwardly extending string of air pipe may be connected in stands in the usual manner, and clamped to oil tubing I5.

The air vent assembly 50 employs an air vent pipe 5! which is preferably secured to the outside of the pipe 25 by welding or similar attachment and this has its upper vent end 52 located above any possible height that the oil may reach in the separated space or chamber between the upper and lower packers. This vent pipe leads down to the float valve housing 30 and has a lower section 52 extending downwardly outside of the end of the iioat valve housing and having an air port connection 53 communicating with the interior of the float valve housing structure 3i). This air port is illustrated as connecting about one-half way between the top and bottom of the iioat valve housing for the purpose hereunder described.

An oil overflow pipe 6,0 is secured or mounted on the outside of the pipe 25 in any usual or known manner such as by welding thereto or the like and has an upper intake end 6I designed when the oil level indicated at 52 is in its uppermost position. This overflow pipe'is immersed and allows downward now of oil through the pipe 66 for the purpose hereunder designated. This oil overflow pipe has a ported connection 63 to the float valve housing adjacent the bottom thereof, the purpose being described hereunder.

The float valve housing is constructed substantially as follows having reference particularly to Figs. 2, 3 and 4. The pipe 25 with its lower portion 2@ is preferably cylindrical and the float valve housing 36 has an inner side 55 concentric with the pipe section 26, an outer side 66 also concentric and the opposite ends 67, @3. It has a bottom closure wall E9 with a valve seat I0 therein. This valve seat may be arcuate conforming to the curved shape of the bottom 69. The top 'el is closed except for a conduit entrance hereunder describ-ed and is also arcuate, thus forming a closed oat valve chamber. In this valve housing there is mounted the float valve assembly "I5, this having a float 'I6 also prefer` ably arcuate or there may be a number of these oats. The float is provided with a float stem or rod 'VI which extends downwardly and has a cone type of valve plug I8 secured thereto and adapted to engage the seat 'III of the lower end 6@ and form a positive closure. The stem of the float valve operates through a lower guide hub connected by an open spider construction 8| to the sides and/or ends of the housing and an upper section 82 of the stem operates through an upper guide hub 83 also supported by a similar spider or the equivalent 84. The float and its valve plug 'I8 are thus mounted for straight reciprocating motion.

An electric cable assembly has a cable extending downwardly from the top of the well between the oil tube I5 and the Well casing and preferably is structurally a separate unit from the air pipe G5 but manifestly these may be connected together where such is desired. The electric conduit or cable however is properly insulated so that the conducting wires are not exposed. This conduit has an oil tight lead in section QI extending from the portion outside ofthe oil tubing to the inside of the pipe I'I below the upper check valve assembly IS. From thence there is a downwardly extending cable sectiony B2 leading through the upper packer assembly 2|l. There is an outwardly extending section 93 of the cable leading outwardly through the pipe and from thence there is a downwardly extending section 94 which may be secured to the outside surface of the pipe 25. This cable has an oil and gas tight connection indicated at 95 to the top wall TII oi the fioat valve housing 30.

The control equipment for compressing the air or gas for pumping and creation of the vacuum or suction employs an electric switch assembly designated IllIl, note particularly Figs. 3 and 5. This employs two mercury switches ItI and |02, each having a pivotal mounting as m3 and Ifl to a fixed part or structure of the float valve housing 3i). Considering the assembly of switch IUI, this is shown as having a link |95 connected thereto which is itself pivoted to a double lever IIIG, pivoted at Ill'I to a fixed structure, this lever having a projecting end |08 aligned to engage a neck or reduced collar |09 on a stem or rod I I l) connected to a toggle lever and spring assembly II5, note Fig. 3. This assembly employs a pivoted arm II5 pivoted at II'I to a bracket IIB depending from the top II of the valve housing. The rod or stem I iii is pivotally connected at Il@ to the arm H5 with a somewhat loose pivot so that the stem III! has a direct reciprocating motion through a guide |20. A second toggle arm I2I is mounted on the same pivot IIl and has an operating rod |22 pivotally connected thereto and attached at the bottom |23 to the float 16. A toggle acting spring |24 connects the opposite ends of the arms I2I and IIio. The stop |25 is utilized to limit the downward motion of the arm IIB.

The mercury switch |02 has a projecting rod |36 positioned to be engaged by the reduced neck or the collars |08 on the stem I IU. It will therefore be seen that as the float 'I5 rises and falls, the movement of the lever arm I2I past the center in moving the spring also past such center causes the spring to give a quick action to the arm IIb` and hence a snap movement to the stem IIil and a quick reversal of the mercury switches. These switches it will be noted operate in a diametrically opposed manner, that is, when one switch is closed, the other switch is open and vice versa.

The operating or control connections to the ground from the switch assembly includes leads from the switch im, these being connected to a relay |35, there being an intermediary power source |31. From the switch Illl there is a second pair of leads |38 to the relay |39 having the source of power IM. The power source is illustrated as a battery. Manifestly these relays may be utilized to give a signal or indication to an operator who may manually control or actuate the devices for controlling the compression of the air or gases in the pump portion of the assembly and the creation of the vacuum in the lower portion of the pump equipment to develop the flow of oil from the ground formation.

However an automatic control is illustrated. The air pipe t5 is indicated in Fig. 5, this leading to the top of the well. In connection with this I employ a compression assembly |45. This has a compression tank |46 in which air is substantially continuously charged into the tank by a compressor Idil', this compressor being operated in any suitable manner as by an electric motor. A supply pipe Ill8 leads from the compression o di tank |45 to the pipe 45 through the medium of a three-way control valve |49. The drawings illustrate a diagrammatic manner of operating a control circuit to electrically operate the valve, this having the power lines |55 operated by the relay assembly |35 for opening and closing and having an actuating means |53 with a delayed action to operate the valve Iflll, this valve having an exhaust port |51? to exhaust the compressed 'air to atmosphere. There is also a vacuum tank assembly |55 which employs a vacuum tank |56, this being under a continuous suction by a suction pump Il preferably actuated by an electric motor. A suction or vacuum pipe Itii leads through a closure valve .|59 to the airpipe 45.

This valve is controlled electrically by the relay |39, there being power leads Ill) through the relay |39 and illustrated in diagram as having electrical connections I'iI and an electric means to turn the valve |69.

In deep wells, above the check valve assembly Iii, it may be desirable to operate a mechanical pump such as a lift pump and this is indicated by the assembly numeral |75, note Fig. 1, which has the sucker rod |16. As this is a standard type of pump, it is not described or illustrated in detail.

The cycle of operations after the packers have been set and the equipment is ready for operation may be considered substantially as follows:

with the valve 'I8 seated and thus closed, the float 'Iii is in its lowermost position and thus the oil has been exhausted from the float valve assembly by iiowing downwardly out of the port and thence the oil may be considered as having been forced upwardly by the air pressure and in such positive forcing of the oil upwardly, the standing valve 3'! is closed. The electric switches have been set by the movement of the Float valve so that the valve I it first exhausts from pipe A5 to the atmosphere and then is closed, shutting olif the connection between I5 and the atmosphere and the compression tank Illia'. The valve It@ has been actuated and, due to a suitable time delay, forms a vacuum connection through pipe |68 to the air pipe d5 and the vacuum tank Iiii. This exhausts the air from the space between the upper and lower packers, the air` in such space centering at the port 47 and being exhausted upwardly. This relieves the pressure between the packers. It also relieves the pressure above the standing valve 3l so that oil is drawn in from the well formation through the intake of pipe 38 upwardly through the standing valve 37|, flowing outwardly 4 through the upper end of the pipe This oil fills up the space between the two packers rising above the float valve housing and assembly 35 until the level of the oil indicated at 52, note Fig. l, rises above the level of the top of the oil pipe Ell, this being a downward iiow pipe. The oil therefore drains downwardly through the pipe 5I), the lower part of the float chamber and fills this with oil above the closed valve It. Such action causes a rising of the float i5 and at the same time an exhaustion or venting of the air in this float chamber through the air port 55 and the air Vent pipe 5ft. This air is discharged at the upper open end 52 above the possible level of oil between the two packers. When the float I5 rises to a suicient height, it reverses the position of the mercury switches. It will be noted however that this action only takes place substantially when the oil has accumulated to its maximum amount as the oil does not enter the float chamber until the oil has risen above the top 6! of the pipe 6i). rIhis reversal of the mercury switches may be used to give a signal to an operator at the top of the well who may manually control the change from suction to compression but in the automatic arrangement the valve |69 leading to the vacuum tank E58 is closed, thus shutting oif the connection from the pipe 65. The valve m9 connecting the air pipe 45 and the compression tank |46 is opened, thus allowing a quick and sudden charging of the air pump with air under compression, this flowing downwardly through the air pipe 45 and out of the port 41 below the upper packer. This air pressure manifestly issuiciently great to force the oil downwardiy around the oil pipe 26 and upwardly through the intake at the bottom 3l and past the check valve i6, thus giving a lift to the column of oil. The air pressure also acting down through the vent pipe 5E) into the float chamber causes an expulsion of the oil through the downow oil pipe 6G and through the open port 'i8 so long as this is open. However the oil remains in the iioat chamber until the level of oil between the two packers has been reduced to permit the float to drop and thereby closing the port 'i8 and again reversing the switches. The cycle of operations is then repeated.

Various changes may be made in the details of the construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. An air lift for oil comprising in combination a well casing, an oil tube with a check valve extending downwardly in the well easing, an upper sealing means between the lower end of the tube and the casing, an oil pipe extending downwardly in the well casing from the sealing means and having an inlet opening at the bottom and a flow communication with the oil tube, a lower sealing means in the well casing and an intake oil pipe extending downwardly therefrom and having a standing valve, said intake oil pipe delivering to the space between said upper and lower sealing means, an air connection from below the upper sealing means and above the lower sealing means connecting to the top of the well adapted for flow of compressed air or gases to the space in the easing between the two sealing means and for the exhaust of air therefrom whereby oil from the said space may be forced upwardly through the rst mentioned oil pipe and tube due to the positive air pressure and, on the decrease of such air pressure, oil due to a differential pressure in the well formation and in the said space flows into such space, a iioat valve casing having a float controlled valve therein located in the said space between the upper and lower sealing means and below the air connection, an air vent leading from said iioat valve casing, a downiiow oil pipe extending from said space into said neat valve casing and upwardly towards the upper sealing means, and means at the top of the well actuated by the rise and fall of the float valve and responsive thereto to control the air flow in said air connection.

2. An air lift for oil comprising in combination a well casing, an oil tube with a check valve extending downwardly in the well casing, an upper sealing means between the lower end of the tube and the casing, an oil pipe extending downwardly in the well casing from the sealing means and having an inlet opening at the bottom and a flow communication with the oil tube,

a lower sealing means in the well casing and an intake oil pipe extending downwardly therefrom and having a standing valve, said intake oil pipe delivering to the space between said upper and lower sealing means, an air connection from below the upper sealing means and above the lower` sealing means connecting to the top of the well adapted for flow of compressed air or gases to the space in the casing between the two sealing means and for the exhaust of air therefrom whereby oil from the said space may be forced upwardly through the first mentioned oil pipe and tube due to the positive air pressure and, on the decrease of such air pressure, oil due to a differential pressure in the well formation and in the said space ows into such space, a oat valve housing mounted on the oil pipe and positioned above the intake of said pipe above the lower sealing means, a iioat valve therein, an air vent pipe connected to the upper part of the housing and extending upwardly along the oil pipe to a position below the said air connection, an oil downow pipe extending upwardly along the oil pipe from the float valve housing for downow of oil therein, and an electric switch means with electric circuits, the switch means being operatively connected to the oat valve and the cir-cuits having a connection to the top of the well with means responsive to the position of the oat valve to control the air flow in said air connection,

3. An air lift for oil comprising in combination a well casing having means at the bottom for the intake of oil from the well formation, an oil tube extending downwardly and having an Lipper packer, said oil tube having a check valve therein, an oil pipe extending downwardly from the packer and having an inlet for oil at the bottom, a lower packer below said inlet for oil, a lower oil pipe discharging upward in the space between the two packers extending downwardly from the lower packer and having an inlet with a standing check valve, an air pipe leading from the top of the well and provided with an air port located adjacent the upper packer communicating with the space defined by the two packers and the casing, means to force air under pressure downwardly through said pipe to create a pressure on oil in the said space and force such oil upwardly through the oil pipe, the oil tubing and the check valve thereof, means to release such air pressure whereby the pressure may be reduced to create a diierential pressure between that of the well in the formation and the pressure in the said space, a oat valve housing having an oil actuated float control valve, an air vent pipe connected from said housing and extending upwardly to a position above any possible elevation of oil level in the space between the two packers, a downow oil pipe connected to the said housing and extending upwardly and having an open upper end located below a possible low oil elevation in such space whereby on the oil rising in the said space, such oil ows downwardly in the downflow oil pipe to the said housing, causing an opening of the float valve, the air in the said housing being vented through the air vent, and means at the top of the well associated with the iiow of air in the air pipe actuated by the rise and fall of the float valve and responsive thereto to control the air flow in said air pipe.

4. An air lift for oil comprising in combination a well casing having means at the bottom for the intake of oil from the well formation,

an oil tube extending downwardly and having an upper packer, said oil tube having a check valve therein, an oil pipe extending downwardly from the packer and having an inlet for oil at the bottom, a lower packer below said inlet for oil, a lower oil pipe discharging upward in the space between the two packers extending downwardly from the lower packer and having an inlet with a standing check valve, an air pipe leading from the top of the well and provided with an air port located adjacent the upper packer communicating with the space dened by the two packers and the casing, means to force air under pressure downwardly through said pipe to create a pressure on oil in the said space and force such oil upwardly through the oil pipe, the oil tubing and the check valve thereof, means to release such air pressure whereby the pressure may be reduced to create a diierential pressure between that of the well in the formation and the pressure in the said space, a float valve housing having an oil actuated oat control valve, an air vent pipe connected from said housing and extending upwardly to a position above any possible elevation of oil level in the space between the two packers, a downilow oil pipe connected to 'the said housing and extending upwardly and having an open upper end located below a possible low oil elevation in such space whereby on the oil rising in the said space, such oil flows downwardly in the downow oil pipe to the said housing, causing an opening of the float valve, the air in the said housing being vented through the air vent, a pair of electric switches, an operating connection between said switches and the float valve, circuit connections from each switch to the top of the Well and an electrical relay means actuated by said circuit and responsive to the rise and fall of the float valve and means controlled by the electrical relay to regulate the air flow in said air pipe.

EUGENE L. BOYNTON. 

